This invention relates to an automated device for processing sample containers through a device which requires a particular arrangement of these containers. More specifically this invention relates to a robotic device, also called a station, which is capable of transferring test tubes from a device which brings sample to be centrifuged to the vicinity of the centrifuge, arranges them in a balanced fashion in centrifuge sample carriers on an intermediate staging area, loads and unloads the centrifuge, and transfers the processed samples to their originating point, or to a third point or device.
Centrifuging is a necessary step in the processing of blood samples in a clinical laboratory setting. Most current clinical tests require that serum or plasma be separated from red blood cells, and other blood debris, before an assay can be run on the sample. Most often this is accomplished by centrifugation, although dialysis- or filtration-type technologies are used in some operations, particularly where only a small quantity of sample is available. But for the most part, centrifugation is an essential preparatory step in the processing and testing of blood samples in a clinical laboratory setting.
Lab automation is becoming a standard in clinical laboratories which do large test volumes. Automation in the large lab context is moving to an assembly-line type operation. Samples are introduced onto an automated sample routing system. Conveyor belt systems are the preferred choice in most automated systems. The system moves test tubes to some predetermined location based on information on the order form associated with that sample which has been fed into the system""s control mechanism. At the predetermined stop, the sample tube is put into a holding pattern, an aliquot is removed, and the aliquot is tested for the analyte as per its order form. See for example U.S. Pat. No. 5,623,415 which is incorporated by reference herein in full.
While several automated routing systems are now marketed or are functioning in captive labs, their through-put is often no faster than the preparation and/or loading step. Centrifugation takes 7 to 10 minutes for cycling through a load of tubes, i.e., loading up the centrifuge baskets, spinning down the blood samples, and unloading the processed tubes. Most if not all sample prep steps involving centrifugation is now done prior to loading tubes onto the automated routing system. In that context, where centrifugation is required, the centrifuge is loaded and unloaded manually off-line, then centrifuged sample tubes are loaded onto the routing system. A manual operation requires staffing, requires additional human handling of tubes, and requires decision making as to which tubes to place in which carrier to achieve a balanced load in the centrifuge. A manual operation can be rate limiting and is more expensive than would be an efficient automated robotics system.
Some attempts have been made to automate the centrifugation step. One system is currently being marketed by Coulter(copyright) Corporation, Miami, Fla., USA. It uses a 4-stage system to prepare samples. Tubes are loaded into racks in an inlet module; the racks are moved via conveyor to a bar-code reader; then the racks move to a centrifuge module which uses a robotic arm to pick tubes needing centrifugation from the racks, loads them directly into the centrifuge baskets in the centrifuge, and returns them directly to the racks on the conveyor; after which the racks are routed to other processing devices prior to being routed to assay stations. One slow step in this operation is the centrifugation loading and unloading operation. The robotic load/unload operation must remain inactive during the centrifuge""s spin cycle; it can not be loading and unloading tubes during the spin cycle since it moves tubes between transport rack and centrifuge tube adaptor in the centrifuge. What is needed is a more efficient system which minimizes the time lost to the overall operation caused by the necessary wait for the centrifuge""s spin cycle to be completed. If some operation could be slotted into this down-time, some operation which has to be done in any event, the overall efficiency of the operation could be greatly enhanced. This invention provides such a solution.
In a first aspect this invention relates to a process for automating the processing of samples through at least one fault-tolerant centrifuge using a device which has a processing station interposed between a tube collection or transport device and a fault-tolerant centrifuge, the station comprising:
a) a staging area for tube adaptors compatible with the centrifuge;
b) a dual function tool having:
i) a tube gripper which can recognize and adapt to tubes of different heights and diameters on the tube collection or transport device and which routes tubes between the tube collection or transport device and the centrifuge adaptors on the staging area; and
ii) an adaptor gripper capable of transporting adaptors to and from said centrifuge, the process comprising:
a) under automated control:
(1) identifying the height and diameter of a tube on the tube collection or transport device;
(2) selecting a tube which have a pre-set height and diameter;
(3) gripping and removing the selected tube from the collection or transport device;
(4) placing the tube in an adaptor on the staging area in a sequence which provides paired adaptors of essentially balanced weight such that when the centrifuge cycles, the weight distribution between the paired adaptors is within the fault tolerance limit of the centrifuge;
(5) placing the filled or partially filled, balanced, paired adaptors into the centrifuge opposite each other;
(6) removing adaptors from the centrifuge to the staging area after the spin cycle; and
(7) picking cycled tubes from the adaptors and placing them on the tube collection or transport device.
It is preferred to carry out the adaptor fill and unload operation during the centrifuge spin cycle.
In a second aspect this invention relates to a robotic device for automating the processing of samples through a fault-tolerant centrifuge, the device comprising:
a) a tube collection or transport device interfaced with,
b) a processing station interposed between the tube collection or transport device and at least one fault-tolerant centrifuge and interfaced with
c) a fault-tolerant centrifuge, the station having
i) a staging area for tube adaptors compatible with the centrifuge; and
ii) a dual function tool having
a) a tube gripper which
(1) recognizes and adapts to tubes of different height and diameter on the tube collection or transport device;
(2) selects tube of only a pre-set height and diameter;
(3) places tubes in paired adaptors in a balanced fashion;
(4) routes tubes between the tube collection or transport device and the centrifuge adaptors on the staging area, and vica versa; and
b) an adaptor gripper capable of transporting adaptors to and from the centrifuge;
c) an electronic control means for controlling the action of the tool in sequence with the operation of the tube collection or transport device, the placement of tubes in adaptors in a balanced fashion, the transport of adaptors to and from the centrifuge in sequence with the cycling of the centrifuge, and the unloading of processed tubes from adaptors.